This invention pertains to the art of rod end mounting arrangements and more particularly to such arrangements where the rod may be subjected to rocking and/or axial forces.
The invention is particularly applicable to mounting assemblies for vehicle suspension system strut rods and will be described with particular reference thereto. However, it will be appreciated that the invention has broader applications and may be adapted to use in other environments.
Vehicle suspension systems utilizing strut rods for supporting, for example, the lower control arms have come to utilize bushing assemblies for yieldably connecting the forward end of the strut rods to a part of the vehicle chassis or frame. These bushing assemblies are designed to be pliable or yieldable to accommodate strut rod pivoting about a point on the frame which is different from the control arm pivot point which is also located on the frame. The pliable nature of the assemblies is necessary to avoid destruction resulting from various forces imposed thereon through the strut rod during vehicle operation.
Typical of prior strut rod mounting assemblies are the ones shown in U.S. Pat. No. 3,552,785 to Elder, et al. Generally, the arrangements shown therein employ a pair of resilient bushings mounted on opposite sides of a vehicle frame member. The bushings include central openings which are aligned with an opening in the frame. A terminal end portion of a strut rod passes through the aligned openings and is connected to the bushing assembly by nuts and washers received at opposite ends of the assembly and which allow each bushing to be slightly compressed at installation. Suitable spacer sleeves are slidably received over the strut rod between the end nuts to insure proper compression of the bushings and to prevent them from engaging the strut rod itself. In addition, each bushing includes a small metal insert molded into the inner end face at generally the radial inner area thereof for providing axially directed pilot flanges. These pilot flanges are adapted to be received in the vehicle frame member opening to act as pilot members for the overall mounting assembly when it is subjected to axial and rocking forces in response to strut rod movement during vehicle operation.
While the general type of strut rod mounting assembly specifically disclosed in prior U. S. Pat. No. 3,552,785 and described above is generally satisfactory, it has a design feature which could potentially cause problems. In particular, the pilot and pivoting portion defined by the small metal insert molded into each bushing could be a cause of premature failure. To explain, during compression and rebound of the suspension system, the strut rod is rocked in the frame member and causes that portion of the bushing closely associated with the metal insert to be constantly pinched and abraided. If the bushings deteriorated from such action, they would no longer properly pilot the strut rod in the frame member opening. This could, in turn, result in undesired and unacceptable front end alignment changes and braking problems.
It has, therefore, been desired to develop a strut rod mounting assembly which would overcome the aforementioned problems and others in order to provide a more reliable strut rod mounting arrangement having a longer effective life for substantially reducing vehicle front end alignment changes and braking problems which could otherwise be caused through improper strut rod support.